Yamaha CP 20 Dynamics Broken

Hello - I have a Yamaha CP 20 and the dynamic keys seem to be broken. It sounds normal when I strick the keys softly or with medium pressure, but as soon as I hammer down the sound gets choked out and doesn’t sustain at the louder dynamic. I sprayed it with deox but that didn’t seem to help.

I also have trouble with the sustain pedal, sometimes it is stuck on. Maybe the two problems are related.

Any help would be greatly appreciated.

thank you,